Mertens has been in phenomenal form for Napoli this season.

Lorenzo Insigne has urged Napoli teammate Dries Mertens to reject Manchester United's advances and stay at the Stadio San Paolo beyond this summer. Mertens, 29, has been in simply sensational form for Mauricio Sarri's men this season and his goals have helped Naples to third in Serie A, just one point behind second placed Roma.

Mertens has scored 28 goals and provided seven assists in all competitions for Napoli this season and has inevitably attracted interest from clubs all around Europe, including United.

The Belgium international is believed to have a release clause of £30m ($38.77m) in his current contract with the Italian outfit, but Insigne, who has also been in fine form for his boyhood club, hopes Mertens resists the allure of Manchester United et al and stay with the Partenopei for years to come.

"Mertens has a lot of quality and can do well in any role," Insigne told Mediaset, relayed by talkSPORT. "His goals are important, I hope he remains with us so that I get to play alongside him for a long time. He's a great player.

"The club knows how to keep its best players. I renewed my contract for a winning project and I hope he can do the same."

After a rather disappointing league campaign, Manchester United are set to spend heavily in the summer. The Red Devils will almost certainly be in the market for a new centre-forward after charismatic Swede Zlatan Ibrahimovic suffered significant ligament damage a couple of weeks ago.

Romelu Lukaku and Antoine Griezmann have both been heavily linked with a move to Manchester United, who will have Marcus Rashford leading the line against Spanish outfit Celta de Vigo in their Europa League semi-final on Thursday evening.

The Red Devils are facing a major injury crisis ahead of the game at the Balaidos, but Mourinho will be able to welcome back midfield duo Paul Pogba and Marouane Fellaini from injury and suspension respectively.